The AGA (Australian Gas Association) (http://www.aga.asn.au/) provides accredited product certfication services with respect to the Gas, Electrical and Plumbing sectors within Australia. It also provides additional certification services that are accepted by the relevant government/industry regulators.

A burner system that, on starting, follows a self-acting sequence that has been manually or automatically initiated, to provide gas and ignition to the burner without any intermediate manual operation.

A normal cessation of operation occurring when a pre-determined operation condition is reached and the operation of the burner to provide the application of heat is no longer required. The equipment is placed into a safe stand-by condition ready to restart on demand; or a shut down to a safe stand-by condition in response to an incorrect condition signal resulting from a fault that is unlikely to be hazardous or is likely to be self rectifying so that normal restarting is permissible when the fault has cleared.

The time required to build up a pocket or concentration of unignited gas of such quantity and proportions that, if ignited, the pressure of the resultant explosion could equal the permissible safe internal pressure of the appliance.

An adjustable device for controlling (a) air flow in a forced or induced draught air system; (b) the flow of flue products in a flue system; (c) the recirculation of air, flue gases or process gases; or (d) the flow of any other fluids.

A system consisting of a flame detector(s) plus associated circuitry, integral components, valves and interlocks, the function of which is to shut off the fuel supply to the burner(s) in the event of ignition failure or flame failure.

The pipe or duct through which combustion products are conveyed from a gas appliance to a discharge point, including any draught diverter, slip joint and associated duct, barometric device, fan or other fittings in the duct and includes the following.

The IP Code (http://en.wikipedia.org/wiki/Ip_rating) (or Ingress Protection Rating, sometimes also interpreted as International Protection Rating) consists of the letters IP followed by two digits or one digit and one letter and an optional letter. As defined in international standard IEC 60529, IP Code classifies and rates the degrees of protection provided against the intrusion of solid objects (including body parts like hands and fingers), dust, accidental contact, and water in mechanical casings and with electrical enclosures.

A motor-driven blower, the suction side of which is supplied with a mixture of air and gas from an appropriate proportioning device, which supplies a burner(s) in the immediate vicinity of the blower and has no control and/or safety device between the blower and burner.

An upgrade to any or all of: gas valve train equipment; combustion/purge air system; flame safeguard system; burner management system (not involving like for like exchange of components) that changes the safety integrity of the existing system or takes the gas appliance out of its original certification criteria.

Pressure (the symbol: p or P) (http://en.wikipedia.org/wiki/Pressure) is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure (also spelled gage pressure) is the pressure relative to the local atmospheric or ambient pressure.

The purge volume includes the combustion chamber and all areas where combustion products and combustible vapours, dusts or gases may accumulate in the appliance or process, up to the vertical connection of a flue or chimney that discharges directly to atmosphere.

A check of a flame safeguard system that will prevent an ignition attempt from occurring if the system is in the flame proved condition before any gas valves are energised as part of an ignition attempt.

A safety shut off system that incorporates two safety shut off valves in series, with the space between the two valves automatically vented. These valves are interlocked so that when the safety shut off valves are closed, the vent valve is open and vice versa.

Single Phase (http://en.wikipedia.org/wiki/Single_phase)electric power refers to the distribution of alternating current electric power using a system in which all the voltages of the supply vary in unison. Single Phase distribution is used when loads are mostly lighting and heating, with few large electric motors.

Thermocouples (http://en.wikipedia.org/wiki/Thermocouple) are a widely used type of temperature sensor for measurement and control and can also be used to convert a heat gradient into electricity. They are inexpensive, interchangeable, are supplied with standard connectors, and can measure a wide range of temperatures.